Gun barrel and barrel mounting



NOV. 13, 1934. s GREEN 1,980,399

GUN BARREL AND BARREL MOUNTING Filed Nov. 23, 1931 INVENTOR. Samuel B Green BY h/W- MM ATTORNEY Patented Nov. 13, 1934 UE'TE garter t ies 4 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1923; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a gun barrel and barrel mounting.

In the water-cooled type of gun, the barrel is surrounded by a water jacket and since it has a reciprocatory movement relative thereto, it is necessary to provide a packing for the movable joint to prevent leakage of the cooling medium. According to the present method of packing this joint, the packing material is in direct contact with the barrel and detrimentally aliected by being subjected to the heat of the barrel. Also because of the direct contact between the packing and barrel the muzzle end of the barrel is denied access to the cooling medium.

The principal objects of the present invention are to construct the barrel and its mounting so that the packing will be better protected against the heat of the barrel and the rifled muzzle end of the barrel will be available to the cooling medium in the jacket during reciprocation. A further object is to provide a mounting which lends itself to the provision of a reserve water space in front of the muzzle end of the barrel.

With the foregoing and other objects in View, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

Fig. 1 is a longitudinal sectional view through the muzzle end of a water-cooled machine gun with the barrel in battery and showing one manner of carrying the invention.

Fig. 2 is a fragmentary View similar to Fig. 1, showing the barrel in position of full recoil.

Fig. 3 is a longitudinal sectional view illustrating a modification of Fig. 1.

Fig. 4 is a longitudinal sectional view showing the mounting of a barrel with a modified muzzle extension.

Fig. 5 is a longitudinal sectional view of a further modified muzzle extension.

Referring to Fig. 1, there is shown the front portion of a machine gun barrel 5 disposed in a jacket 6 adapted to contain a cooling medium. The front plate 7 of the jacket includes a bearing member 8 having a flared rear end 9 to facilitate introduction of the barrel unit. When the barrel is in the in-battery position, the muzzle end reaches only a short distance within the bearing 8 so that when in the position of full recoil as 3 seen in Fig. 2 it will be accessible to the cooling medium in the jacket.

A sleeve 10 secured to the forward end of the barrel by a threaded connection 11 forms an extension of the barrel whereby it is supported in the bearing member. A gland l2 embracing the sleeve fits in a counterbore 13 of the bearing member and has a threaded connection 14 with the wall thereof. The gland serves to confine and compress a packing member 15 against the 7 shoulder 16 of the bearing member and an effectual seal is established to prevent leakage of the cooling medium.

The packing embraces the sleeve preferably opposite the threaded connection 11 and in sumcient proximity to the rear end of the bearing 8 so that the portion of the sleeve normally contacting the packing when the barrel is fully forward will be accessible to and subject to the cool ing action of the liquid in the jacket when the barrel moves in recoil. Since a joint such as the threaded connection 11 affords an obstacle to the conduction of heat, the heat from the muzzle end of the barrel will not be transmitted to the packing in the same degree as would be the case if the joint were not present.

It will be noted that in the fully forward or inbattery position, the sleeve 10 projects beyond the front face of the gland 12 only a slight distance. This distance corresponds to the recoil distance of the barrel during the time the projectile travels through the barrel so that, as the projectile leaves the muzzle, the muzzle will be flush with the front face of the gland. This provision prevents a gas blow-back on the gland and undesirable reactions on the barrel and projectile.

By terminating the rifled barrel short of the front plate '7 of the jacket the body of liquid in the jacket will consequently extend forwardly of the muzzle. This feature is of especial significance in high angle firing because it will insure an ample supply of liquid to cover the rifled barrel despite the losses occasioned by the conversion of some of the water into steam which is 105 permitted to escape.

In the modification shown in Fig. 3, the barrel 17 has been shortened so that the threaded connection 18 between the barrel and sleeve 19 is well within the body of liquid. A liner 20 placed. 110

inside the sleeve in front of the barrel provides insulating advantages for the packing 21.

In Fig. 4, the sleeve 22 has an external diameter in excess of the diameter of the muzzle of the barrel 23 and equal to the diameter of the rear or breech of the barrel. This facilitates the formation and alignment of the front and rear bearings, respectively 24 and 25, in the jacket and reduces the vibration error of the barrel.

In Fig. 5 the sleeve 26 is present as an integral tubular extension of the rifled barrel 2'7, and has a considerably larger bore than the bore of the barrel. The inner wall 28 is forwardly flared to insure a uniform reduction in back pressure to the gases of discharge. The packing 29 is positioned so that it will always embrace the extension irrespective of the movement of the gun barrel.

I claim:-

1. In combination, a cooling jacket of a machine gun having a front plate with a shouldered bearing, a gun barrel movable with respect to the jacket, a sleeve having a threaded connection with the muzzle of the barrel and disposed in the bearing, a gland embracing the sleeve and secured to the bearing, and a packing embracing the threaded connecting portion of the sleeveand held against the shoulder of the bearing by the gland.

2. In combination, a cooling jacket of a ma;---

chine gun having a front plate with a bearing, a gun barrel movable with respect to the jacket, a tubular extension on the muzzle of the barrel having an enlarged bore and disposed in the bearing, a packing between the tubular extension and bearing, means for confining the packing, and a heat insulating lining for the tubular extension.

3. An automatic gun embodying a reciprocable barrel, a cooling jacket surrounding the barrel, the rifled portion of the barrel lying within the confines of the jacket, a support for the muzzle of the barrel at the forward end of the jacket, a packing in said support for confining a cooling medium within the jacket, the packing positioned to be surrounded by the cooling medium, and a gland adjustable to tension the packing extending without the jacket.

4.. An automatic gun embodying a reciprocable barrel, a cooling jacket surrounding the barrel, a bearing in the forward end of the jacket positioned to be surrounded by a cooling medium within the jacket, an extension on the muzzle of the barrel sliclable within the bearing, and a packing within the portion of the bearing contacted by the cooling medium.

SAMUEL G. GREEN. 

